Ideal Response 120 Ignition

[dalekwho]

Hello

My Ideal Response 120 gas combi boiler will not ignite the central heating from cold first thing in the morning.

The CH light is on correctly and the boiler is whirring (the fan?)

If I turn off the mains and on again and then turn on the hot water tap it ignites, sometimes second or third attempt. It is then fine until the next morning including the central heating so seems to be a problem only from absolute cold.

You can see the ignition light flicker at point of ignition but not 'take hold'
The ignition has not locked, the pressure bar is always kept about 1.8 cold, no sign of leaks in the fan or HE, and the electrodes were recently cleaned at a service.

Is this a gas valve problem, an ignition problem or a exchanger problem?
I want to try and get another 3 years out of the boiler (7 years old) since I want to disrupt all the kitchen only at the next full refurb.

Many thanks

 

[superdupergasman]

Low gas pressure when igniting, sensing electrode faulty, burner problem, gas valve problem, PCB fault..... could be any one or a number of the above.

 

[dalekwho]

Many thanks
A Corgi Engineer has replaced the gas valve and fitted new electrodes and problem still persists. It remains intermittent (about 50% does not fire up) but seems worse from dead cold where it always takes several attempts.
Fan is on, gas is on, ignition board clicks and sends spark, boiler lights or otherwise attempts to light but goes out in a second.
Engineer is stumped and now thinks Ignition PCB but its a nightmare buying expensive parts that are not needed. Works fine when fired up and seems easier to fire up on hot water rather than heating.
Any views?

 

[namsag]

Could be the actual meter govenor sticking first thing. if its doing it every morning to test it get up and turn cooker or fire on/off first a few times then if boiler lights first time everytime you know its meter related.

 

[petit_pablo]

Spark generators are known to be bad, can give intermittant or weak spark. Also much cheaper than the board